You could try an ice pack on your forehead or the back of your neck
You could also try having an orgasm, I know that helps me. I also drink a bit of caffeine, while taking tylenol and cover my eyes with a cool towel and an icepack on my neck. Both things work for me. I also get migraines and my migraine meds are off limits!
Just because it's a class C doesn't make it unsafe. It's just not been studied enough to tell. Also if it was unsafe it would be in the first trimester when baby is developing. You're past that stage. I took it while pregnant and my baby girl was fine. I also have to take a couple other pain meds that are class C. My baby currently has no defects either. I'm 21 weeks tomorrow. If it's a bad headache, I'd try it. One dose won't hurt the baby. Also it sounds like it may be a migraine. I would get yourself a slushie/icee and drink it quickly enough to give yourself a brain freeze. It should relieve the migraine. It sounds hokey and made up, but it really does work. A migraine is when the blood vessels in your brain dilate too quickly, when you have a brain freeze it is your brain thinking you're freezing to death and it shrinks the blood vessels down to preserve itself. It doesn't realize it's just a cold beverage. You can try this first and if for whatever reason it doesn't help, if it was me... I'd take the Fioricet/Butalbital. Good luck sweetheart. I've been there!